Cable grapple

ABSTRACT

A grapple for hoisting an undersea cable having first and second cable engaging jaws which are normally biased in a closed position. The first and second jaws are pivotally connected to a guide plate at a common pivot point and a restraining wire is provided to keep the jaws in an opened position. Upon locating a cable undersea, the restraining wire is severed and the biased jaws are closed around the cable. A cam surface is provided on the guide plate and a shaft which is attached by linkage to the first and second jaws moves onto the cam surface to lock the jaws in a closed position around the cable to be recovered.

United States Patent 1 Adkins et al.

[451 Mar. 25, 1975 CABLE GRAPPLE [73] Assignee: The United States ofAmerica as represented by the Secretary of the Navy, Washington, DC.

[22] Filed: Feb. 21, 1974 [21] Appl. No.: 444,208

[56] References Cited UNITED STATES PATENTS 1,266,233 5/1918 Eckerson294/112 X 7/1949 .lellison 294/110 R X 2,621,069 12/1952 Anguera 294/110R X 2,745,695 5/1956 Peyer 294/110 R X 3,266,353 8/1966 Gretter et a1.294/66 R X 3,572,808 3/1971 Miller 294/118 Primary Examiner-Evon C.Blunk Assistant Examiner-Johnny D. Cherry Attorney, Agent, or FirmR. S.Sciascia; Paul S. Collignon [57] ABSTRACT A grapple for hoisting anundersea cable having first and second cable engaging jaws which arenormally biased in a closed position. The first and second jaws arepivotally connected to a guide plate at a common pivot point and arestraining wire is provided to keep the jaws in an opened position.Upon locating a cable undersea, the restraining'wire is severed and thebiased jaws are closed around the cable. A cam surface is provided onthe guide plate and a shaft which is attached by linkage to the firstand second jaws moves onto the cam surface to lock the jaws in a closedposition around the cable to be recovered.

2 Claims, 4 Drawing Figures CABLE GRAPPLE BACKGROUND OF THE INVENTIONThe present invention relates to a grapple and more particularly to acable grapple for attachment to a severed cable that is undersea.

Various grapple devices are available for lifting and moving objects andsome grapple devices are specifically designed to lift cables. As iswell known in the art, ocean communication cable, which is also known asunderwater or submarine cable, extends usually between differentcontinents and is laid on the floor of an ocean where it is subjected tothe hazard of becoming damaged by various causes, such as by the actionof marine organisms or by becoming fouled in trawling gear operated byfishing boats. In addition, there may be failures of electronicassemblies, such as repeaters and equalizers, which are commonlyconnected into the cable at spaced intervals along its length. Thus, anyone of a number of factors may make it necessary to find an underwatercable and pull it up above the surface of the water so that it can beexamined and repaired. The process of finding a cable and pullingit upis called cable-retrieval or cable-recovery.

In general, underwater cables have been retrieved by means of grapnelsdragged by cable-recovery ships. The usual procedure is firstly toestimate the approximate latitude and longitude of the particular cableportion that is to be retrieved. This can be accomplished by referringto the operational record that was made when the cable was laid. Afterthe approximate position ofthe cable has been determined, acable-recovery ship is sent to this location and a grapnel is lowered tothe ocean floor.

The ship is then caused to travel back and forth in this area whiledragging the grapnel in directions that are at right angles to theestimated axial direction of the cable. When the cable is eventuallycaught or engaged by the grapnel, the grapnel and the engaged portion ofthe cable are pulled up to the ship so that this section of the cablecan be examined and repaired on the deck of the ship. After thenecessary repairs have been made, this section of the cable is returnedto its former position on the ocean floor.

One grapnel specifically designed for retrieving underwater cable isshown and described in US. Pat. No. 3,266,353, entitled, Equipment ForRetrieving Underwater Cable, which issued Aug. 16, I966, to Ralph W.Gretter; et al. In this patented device, a grapnel is provided withflukes for guiding an engaged or hooked cable into a slot in the body ofthe grapnel. A pair of cable grippers are then engaged with the cableand the cable is severed between the two grippers. Ropes, which areconnected to the grippers are then hoisted to raise the severed cable tothe surface. The main disadvantage of this patented device is that itcan only be used with a cable that is not broken or severed, as theflukes cannot engage a cable end.

SUMMARY OF THE INVENTION The present invention provides an improvedgrapple for recovering a broken undersea cable and is designed to beoperated from an underwater research vessel. A line is attached to thegrapple and upon locking around a cable the grapple is separated fromthe underwater research vessel.

The grapple is comprised of a pair of cable engaging jaws that areconnected to a guide plate at a common pivot point. Springs are providedto normally bias the jaws in a closed position and a restaining wire isprovided to keep the jaws in an opened position until it is desired toclose the jaws. An explosive device is provided to sever the restrainingwire whereupon the jaws close. A slot is provided in the guide plate anda shaft is slidably positioned in the guide plate and links connect thisshaft with the cable engaging jaws. A trunnion plate is also attached tothe shaft and has a hole for attaching a lifting cable. Upon closing ofthe cable engaging jaws, the shaft moves out of the slot in the guideplate and onto a cam surface that locks the grapple in a closedposition.

It is therefore a general object of the present invention to provide animproved grapple for recovering an undersea cable.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in I conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view, partiallybroken away, of a preferredembodiment of the present invention;

FIG. 2 is a side view of the preferred embodiment shown in FIG. 1;

FIG. 3 is a perspective view of the cable gripper shown in FIG. 1 withthe jaws being in an opened position around a cable; and

FIG. 4 is a perspective view showing the cable grip per of the presentinvention locked on a cable.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, aU-shaped guide plate 11 is attached to an arm 12 which is connectablewith an attachment on an underwater research vessel. The arm 12 andattachment are constructed so that they can be readily disconnected fromone another. First and second cable engaging jaws 13 and 14 arepivotally connected to guide plate 11 by a shaft 15 that is held inplace by retaining rings 16. As best shown in FIG. 2 of the drawings,the upper portion of jaw 13 is forked and jaw 14 extends through theforked portion of jaw 13. Spacers 17 and 18 are provided between jaws l3and 14, and spacers 21 and 22 are provided between the ends ofjaw l3 andU-shaped guide plate 11.

Guide plate 11 has a slot 23 that extends to' a cam surface 24, which isthe top edge of guide plate 11. A shaft 25 is slidably positioned inslot 23 and is retained by spacers 26 and 27 and retaining rings 28.Link 31 is connected to shaft 25 and has its outer end connected to jaw13 by shaft 32 and retaining rings 33. A pair of links 34 and 35 haveone end connected to shaft 25 and their opposite ends are connected tojaw 14 by shaft 36. Link 31 is positioned on shaft 25 between links 34and 35 and a trunnion plate 37 has legs 38 and 39that are connected toshaft 25 and extend between guide plate 11 and links 34 and 35. Trunnionplate 37 is provided with a hole 41 so that a lifting cable can bereadily attached to trunnion plate 37. A spring clip 42 is attached tothe upper portion of jaw 14 and has an arm 43 to which one end ofsprings 44 and 45 are attached. The other ends of springs 44 and 45 areattached to arms 46 on the forked ends ofjaw 13 and springs 44 and 45tend to bias jaws l3 and 14 to a closed position. A third spring 47 hasone end attached to arm 48 on jaw 13 and the other end attached to arm49 on jaw 14, and spring 47 provides an additional biasing force thattends to close jaws l3 and 14.

As springs 44, 45, and 47 will close jaws l3 and 14, a restraining wire55 is provided to hold jaws l3and 14 in an opened position. One end ofwire 55 is attached to arm 56 on jaw 14 and the other end of wire 55 isattached to arm 57 on link 31. A cable cutter 58 is provided to severwire 55 and is preferably an explosive type that is initiated by anelectrical signal. Explosivetype cable cutters are wellknown in the artand basically comprise a piston type punch which is actuated by anexplosive charge. Explosive cable cutters are commercially availablefrom Mine Safety Appliance Co., Pittsburgh, Pa.

Jaws 13 and 14 are provided with inserts 52 and 53 that can be changedto accommodate different size cables 59. Inserts 52 and 53 are selectedso that when jaws 13 and 14 are closed the diameter of a hole formed byinserts 52 and 53 is slightly less than the diameter of cable 59. A slipbar 61 is attached to insert 53 and prevents cable 59 from entering toodeeply into jaws l3 and 14, and thus permits jaws 13 and 14 tocompletely close.

OPERATION Prior to operation, inserts 52 and 53 are selected toaccommodate the particular size cable 59 that is to be recovered. Jaws13 and 14 are then opened and wire 55 attached to keep the jaws in anopened position. When jaws 13 and 14 are fully opened, shaft 25 is nearthe bottom of slot 23 in guide plate 11. A lifting cable is attached totrunnion plate 37, and arm 12 is attached to an underwater researchvessel. This vessel may have an operator inside who looks for cable 59to be recovered, or a television system may be employed and the vesselremotely operated. When the cable is sighted, arm 12 is maneuvered sothat jaws 13 and 14 encompass cable 59. Cable cutter 58 is thenenergized and severs wire 55. Jaws 13 and 14 will spring shut and asthey close, shaft 25 will move up the vertical slot 23 in guide plate 11until shaft 25 clears slot 23 and, upon shaft 25 clearing slot 23, guideplate 11 will be free to rotate about shaft 15 and when arm 12 isreleased from the research vessel, guide plate 11 will rotate and shaft25 will engage cam surface 24 thur locking jaws l3 and 14 on cable 59.This engaging or wedging action of shaft 25 on surface 24 preventsopening of jaws 13 and 14 and loss of cable 59 as the cable grapple andcable 59 are raised by a lifting cable attached to trunnion plate 37.Once cable 59 is aboard a ship, guide plate 11 can be rotated back byhand so that shaft 25 is aligned with slot 23 and then jaws l3 and 14can be opened to release cable 59.

It can thus be seen that the present invention provides an improvedcable grapple which can be locked onto an underwater cable duringlifting operation.

Obviously many modifications and variations are possible in the light ofthe above teachings. it is therefore to be understood that within thescope of the appended claims the invention may be practiced otherwisethan as specifically described.

We claim:

1. A cable grapple comprising,

a guide plate having a cam surface thereon and a slot therein,

first and second cable engaging jaws pivotally connected to said guideplate at a common point,

spring means biasing said first and second cable engaging jaws in anormally closed position,

guide means slidable in said guide plate slot and engageable with saidcam surface a first link connecting said first cable engaging jaw andsaid guide means and a second link connecting said second cable engagingjaw and said guide means whereby said guide means moves in said slotduring closing of said jaws and onto said cam sur face to lock said jawsin a closed position,

a wire connected to said first link and said second cable engaging jawfor holding said first and second cable engaging jaws in an openedposition, and

means for severing said wire whereby said first and second cableengaging jaws are closed by said spring means.

2. A cable grapple as set forth in claim 1 wherein said means forsevering said wire is an explosive cable cutter.

1. A cable grapple comprising, a guide plate having a cam surfacethereon and a slot therein, first and second cable engaging jawspivotally connected to said guide plate at a common point, spring meansbiasing said first and second cable engaging jaws in a normally closedposition, guide means slidable in said guide plate slot and engageablewith said cam surface a first link connecting said first cable engagingjaw and said guide means and a second link connecting said second cableengaging jaw and said guide means whereby said guide means moves in saidslot during closing of said jaws and onto said cam surface to lock saidjaws iN a closed position, a wire connected to said first link and saidsecond cable engaging jaw for holding said first and second cableengaging jaws in an opened position, and means for severing said wirewhereby said first and second cable engaging jaws are closed by saidspring means.
 2. A cable grapple as set forth in claim 1 wherein saidmeans for severing said wire is an explosive cable cutter.